The dome of St. Paul's is said to be
the second largest in the world after St. Peter's in Rome but the construction
is very different - St. Paul's has a wooden dome covered with lead, while St.
Peter's is of stone and brick. The ingenious part of Wren's dome is the hidden
internal structure that is necessary to support the heavy lantern that sits on
the top. The bus swings past the front of the cathedral which is the main
ceremonial entrance. Unusually for a church, there is an admission charge to go
inside.